Fluid delivery device with heat activated energy source

Abstract

An implantable fluid delivery apparatus for infusing medicinal fluids into a patient that includes a novel heat responsive polymer gel material that, upon being heated by a heating coil uniquely functions as an internal energy source for expelling the medicinal fluids from the device.

I claim:  
     
       1. An implantable device for implantation within a patient for infusing medicinal fluid into the patient at a controlled rate comprising: 
       (a) a housing having an outlet;  
       (b) a fluid reservoir containing a fluid disposed within said housing, said fluid reservoir having an inlet and an outlet in communication with said outlet of said housing;  
       (c) a heat stimulated mass disposed within said housing proximate said reservoir, said mass comprising a semi-solid, which upon being stimulated, will act upon said fluid within said reservoir to cause said fluid to flow outwardly of said outlet of said reservoir; and  
       (d) stimulation means for stimulating said mass, said stimulation means comprising a source of heat.  
     
     
       2. The device as defined in  claim 1  in which said mass is disposed within an expandable structure disposed within said housing. 
     
     
       3. The device as defined in  claim 1  further including means for forming said reservoir said means comprising a second expandable structure disposed within said housing. 
     
     
       4. The device as defined in  claim 1  in which said mass comprises a gel. 
     
     
       5. The device as defined in  claim 1  further including a cannula connected to said housing and communicating with said reservoir for delivering fluid from said reservoir to the patient. 
     
     
       6. The device as defined in  claim 1  further including an ullage disposed within said housing and located proximate said fluid reservoir. 
     
     
       7. The device as defined in  claim 1  in which said stimulation means comprises a heat plate disposed proximate said mass. 
     
     
       8. The device as defined in  claim 1  further including fill means in communication with said reservoir for filling said reservoir. 
     
     
       9. The device as defined in  claim 8  in which said housing comprises a base and a cover superimposed over said base and in which said fill means comprises a septum disposed within said cover, said septum being pierceable by a cannula inserted into said septum. 
     
     
       10. An implantable device for implantation within a patient for infusing medicinal fluid into the patient at a controlled rate comprising: 
       (a) a housing having an outlet;  
       (b) a fluid reservoir containing a fluid disposed within said housing, said reservoir having an inlet and an outlet in communication with said outlet of said housing;  
       (c) a heat stimulated, expandable polymer gel disposed within said housing, said polymer gel upon being stimulated, expanding to act upon said fluid within said reservoir to cause said fluid to flow outwardly of said outlet of said reservoir; and  
       (d) stimulation means for stimulating said polymer gel, said stimulation means comprising a source of heat.  
     
     
       11. The device as defined in  claim 10  in which said polymer gel is contained within an expandable structure disposed within said housing. 
     
     
       12. The device as defined in  claim 10  further including a second expandable structure disposed within said housing, said fluid reservoir being formed by said second expandable structure. 
     
     
       13. The device as defined in  claim 10  in which source of heat comprises a heater wire. 
     
     
       14. The device as defined in  claim 10  in which said source of heat comprises first and second heater plates and a heater wire disposed between said heater plates. 
     
     
       15. The device as defined in  claim 10  further including a flow controlling impedance frit disposed between said fluid reservoir and said outlet of said housing. 
     
     
       16. The device as defined in  claim 10  further including a delivery cannula connected to said outlet of said housing for delivery of fluid to the patient. 
     
     
       17. The device as defined in  claim 10  further including sensor means connected to said housing for detecting changes in the patient's body. 
     
     
       18. The device as defined in  claim 10  further including fill means in communication with said reservoir for filling said reservoir. 
     
     
       19. The device as defined in  claim 10  in which said polymer gel undergoes a change in polymer conformation upon being stimulated by said stimulation mass. 
     
     
       20. A medical device for implantation within a patient for infusing medicinal fluid into the patient at a controlled rate comprising: 
       (a) a housing having an outlet;  
       (b) a fluid reservoir containing a fluid disposed within said housing, said reservoir having an inlet and an outlet in communication with said outlet of said housing;  
       (c) a heat stimulated, swellable polymer disposed within said housing proximate said reservoir, said polymer, upon being stimulated, swelling so as to act upon said fluid within said reservoir to cause said fluid to flow outwardly of said outlet of said reservoir;  
       (d) stimulation means for stimulating said expandable polymer, said stimulation means comprising a source of heat; and  
       (e) delivery means connected to said outlet of said housing for delivering fluid to the patient.  
     
     
       21. The device as defined in  claim 20  in which said polymer comprises a phase transition polymer gel. 
     
     
       22. The delivery devices defined in  claim 20  in which said delivery means comprises an elongated cannula having a first end connected to said outlet of said housing and a second end terminating in a porous tip. 
     
     
       23. The device as defined in  claim 20  in which said polymer is contained within an expandable structure disposed within said housing. 
     
     
       24. The device as defined in  claim 20  further including a second expandable structure disposed within said housing, said fluid reservoir being formed by said second expandable structure. 
     
     
       25. The device as defined in  claim 20 , further including interactive sensor means connected to said housing for sensing physiological changes in the patient. 
     
     
       26. The device as defined in  claim 20  further including fill means carried by said housing for filling said reservoir. 
     
     
       27. The device as defined in  claim 26  in which said fill means comprises a septum carried by said housing, said septum being pierceable by a cannula inserted into said septum. 
     
     
       28. An implantable device for infusing medicinal fluid into the patient at a controlled rate comprising: 
       (a) a housing having an outlet, said housing being implantable within the body of the patient;  
       (b) a fluid reservoir containing a fluid disposed within said housing, said fluid reservoir having an inlet and an outlet in communication with said outlet of said housing;  
       (c) a heat stimulated, expandable mass disposed within said housing proximate said reservoir, said expandable mass comprising a semisolid, which upon being stimulated, will act upon said fluid within said reservoir to cause said fluid to flow outwardly of said outlet of said reservoir; and  
       (d) stimulation means for stimulating said expandable mass, said stimulation means comprising:  
       (i) a heating coil disposed within said housing proximate said expandable mass; and  
       (ii) means disposed outside the patient's body for heating said heating coil.  
     
     
       29. The device as defined in  claim 28  in which said means for heating said coil comprises: 
       a. a first antenna coupled with said heating coil; and  
       b. radio frequency transmitting means, including a second antenna disposed proximate said first antenna for controllably heating said heating coil.  
     
     
       30. The device as defined in  claim 29  in which said radio frequency transmitting means includes a controller. 
     
     
       31. The device as defined in  claim 28  in which said polymer gel is contained within a first expandable bellows disposed within said housing. 
     
     
       32. The device as defined in  claim 28  further including a second expandable bellows disposed within said housing and operably associated with said first expandable bellows, said fluid reservoir being formed by said second expandable bellows. 
     
     
       33. The device as defined in  claim 28  further including fill means carried by said housing for filling said reservoir.